A method for preparing nano-magnesium oxide by plasma high-temperature pyrolysis

A nano-magnesium oxide, plasma technology, applied in magnesium oxide, nanotechnology for materials and surface science, nanotechnology and other directions, can solve the problems of long cycle, low pyrolysis efficiency, high energy consumption, etc., and achieve fast heating speed , the effect of high pyrolysis temperature and simple pyrolysis process

Active Publication Date: 2015-12-09
TSINGHUA UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] The purpose of the present invention is to provide a method for preparing high-purity nano-magnesium oxide by plasma high-temperature pyrolysis, so as to overcome the problems of long period, high energy consumption and low pyrolysis efficiency in traditional high-temperature pyrolysis processes

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  • A method for preparing nano-magnesium oxide by plasma high-temperature pyrolysis
  • A method for preparing nano-magnesium oxide by plasma high-temperature pyrolysis

Examples

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Effect test

Embodiment 1

[0038] Using argon as the working gas and shielding gas, the flow rates are 0.2m 3 / h and 4m 3 / h, pass it into the radio frequency plasma torch, trigger the thermal plasma, the plasma power is 10kW, and form the plasma high temperature arc area. With oxygen as carrier gas, the flow rate is 0.1m 3 / h, using the remaining bischofite solution after extracting bromine and potassium from salt lake brine as raw material, concentrated to MgCl 2 The percentage content is 35%, and the insoluble impurities are removed by filtration. The bischofolite solution is sprayed into the plasma high-temperature arc area through the feeding spray gun at a feed rate of 1ml / min by an advection pump to form high-temperature pyrolysis products. The high-temperature pyrolysis product enters the water-cooled down-bed reactor for rapid cooling, and the outlet temperature is 245°C. A gas-solid separator is used to collect solid materials in the gas-solid mixture after quenching to obtain pyrolysis cru...

Embodiment 2

[0040] With helium as the working gas, the flow rate is 0.2m 3 / h, the air is the protective gas, the flow rate is 4m 3 / h, pass it into the radio frequency plasma torch, trigger the thermal plasma, the plasma power is 10kW, and form the plasma high temperature arc area. With argon as carrier gas, the flow rate is 0.1m 3 / h, using the remaining bischofite solution after extracting bromine and potassium from salt lake brine as raw material, concentrated to MgCl 2 The percentage content is 40%, and the insoluble impurities are removed by filtration. The bischofolite solution is sprayed into the plasma high-temperature arc area through the feeding spray gun at a feed rate of 2ml / min by an advection pump to form high-temperature pyrolysis products. The high-temperature pyrolysis product enters the water-cooled down-bed reactor for rapid cooling, and the outlet temperature is 100°C. A gas-solid separator is used to collect solid materials in the gas-solid mixture after quenching...

Embodiment 3

[0042] Using argon as the working gas, the flow rate is 0.2m 3 / h, oxygen is the protective gas, the flow rate is 4m 3 / h, pass it into the radio frequency plasma torch, trigger the thermal plasma, the plasma power is 10kW, and form the plasma high temperature arc area. With air as carrier gas, the flow rate is 0.1m 3 / h, using the remaining bischofite solution after extracting bromine and potassium from salt lake brine as raw material, concentrated to MgCl 2 The percentage content is 40%, and the insoluble impurities are removed by filtration. The bischofolite solution is sprayed into the plasma high-temperature arc area through the feeding spray gun at a feed rate of 1ml / min by an advection pump to form high-temperature pyrolysis products. The high-temperature pyrolysis products enter the water-cooled down-bed reactor for rapid cooling, and the outlet temperature is 200°C. A gas-solid separator is used to collect solid materials in the gas-solid mixture after quenching to...

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Abstract

The invention discloses a method for preparing nanometer magnesium oxide through a plasma high temperature pyrolysis method, which belongs to the technical field of preparation of inorganic nanometer materials. According to the method, bischofite is used as a raw material, a plasma super-high-temperature rapid pyrolysis treatment is carried out on the bischofite, and a pyrolyzed crude product is simply treated to prepare high-purity nanometer magnesium oxide. The preparation method mainly comprises the following steps: triggering thermal plasma, and maintaining the stable operation of the thermal plasma; directly adding the bischofite into a plasma high-temperature arc zone to carry out pyrolysis; quenching a high temperature pyrolysis product and collecting a rough pyrolysis product; washing, filtering, drying and roasting the rough pyrolysis product to obtain the high-purity nanometer magnesium oxide with particle diameter being smaller than 50 nm and Mgo percentage composition being greater than 99%. The method disclosed by the invention can be used in direct pyrolysis of a large amount of bischofite rest after bromine and potassium extraction of salt lake brine, the pyrolysis speed is fast (within milliseconds), no wastewater is generated in the pyrolysis process, the added value of the product is high, the process is simple, and industrialization is easy to realize.

Description

technical field [0001] The invention relates to a method for preparing high-purity nano-magnesia in the technical field of inorganic chemical industry, in particular to a method for preparing high-purity nano-magnesia by pyrolyzing bischofite through a millisecond-level pyrolysis process by using thermal plasma as an ultra-high temperature heat source. Background technique [0002] Magnesium oxide is an important class of chemical products and high-temperature refractory materials, and those with a particle size of less than 100nm are called nano-magnesia. High-purity magnesia generally refers to fine products with MgO content greater than 99%. It is mainly used to produce high-end magnesium products such as high-purity magnesia and high-purity magnesium hydroxide flame retardant. According to different characteristics and uses, it can be divided into high-purity silicon steel grade magnesia , High-purity medical magnesium oxide, high-purity active magnesium oxide, high-puri...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01F5/06B82Y30/00B82Y40/00
Inventor 程易张海宝曹腾飞
Owner TSINGHUA UNIV
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